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Topic: More noise. (Read 661 times)

Trouble with noise again. I zoomed in on this video more than usual so you can see the problem. I have animation settings, detail at .5, AA of 14 (12 min samples), pnt of .025, Supersample off, soft shadow on sun at 9 samples, mitchell-net, defer atmo enabled (although I turned off cloud), detail blending .5. I even tried shadow samples at 20, but nothing. Why do I have noise on the foliage and even the ground. giza_test_17_1.mp4 (2304.35 kB - downloaded 28 times.)

That does seem like a surprising amount of noise for AA12. The first thing I would try is turning off Soft Shadows to see how much that is contributing to the issue. If you still get a lot of noise, then perhaps your foliage textures are very hard to antialias. I note that it appears to be an issue not only in the trees but also the grass, which is interesting. What are you using for grass models? You could then try Max Samples at AA12 just to see if it's a noise threshold or other adaptivity issue. If that is still too noisy, that supports the theory that there is something particularly hard to antialias about your plant textures or models. You might then take a look at the textures, make sure the alphas/opacity are working properly, and make sure there is not an excess of high frequency noise or other detail in the plant textures.

As with all problems of this sort we can provide the best support and advice if we can see the actual file. But I know that is seldom possible. If you can share any additional info or scene data, you can send it to the support address.

Thanks Oshyan,I will turn off Soft Shadows to see what happens. Then I'll try one with AA12 and max samples. Uploading file with maps to support via www.wetransfer.comBy the way, that was AA14, not 12; it was 12 minimum samples (1/16).

So with soft shadows off, the noise on the hill in the shadow mostly went away. But still about the same noise. For AA12 and max samples, again, there was not really any change. Noise in the grass and foliage. Maybe it is something with the objects.

The foliage of course is quite erratic in opacity, a rough outline, not very smooth. Maybe that's the problem. Perhaps the shadows of grasses and foliage on small displacements on ground (rough sandy) have an influence as well. For the animation, that can maybe be reduced.

The culprit on the ground was dead locusts. When I disabled this, the ground was perfect. They are not an object but a shader (tiff file of locusts) that are spread around the ground. I really wanted them.

I have taken a brief look at your files and I see there are some quite rough/jagged/detailed opacity maps for the leaves. This may be partly responsible for the unusually high aliasing. I question whether such fine detail is really visible at this distance. If you can switch that out it might be better. Alternatively perhaps a procedural opacity map would work (not sure if it would be better, but should be I think).

As for the locusts, do you think they are visible from this distance?? Could it be replaced with a texture that is less detailed?

This tree has a normal opacity map, nothing jaggety, with procedural power fractal in the opacity function as a mask. I did a test without this plugged in, but still noisy. The shadow in the back is from a tree and is quite noisy, but without the tree it's fine. I'm going to change the sun shadows samples from 10 down to 5 or even lower. Is there another way to deal with those shadows? Maybe that's the whole problem. Shadow noise. I did try sunshadows at 20 samples but it didn't help.

Shadow quality when Soft Shadows are not enabled depends on Micropoly Detail. With soft shadows on, it should respond primarily to the number of samples.

I think we need to focus and solve one of these problems first. My suggestion would be to address the noise problem on the trees and other plants, then worry about ground detail. If necessary there are some ground detail options we can look at which may help, but if you can't antialias the trees themselves without prohibitive render time it's a bit of a moot point.

Thanks. I've gone up to AA14, det .5, and pnt .025. Not really any change in noisiness from AA10, det .6, pnt .03. Not sure if going up would be of any benefit, especially if there's an issue with the object or material. Or, maybe I'm asking TG to do something that it can't. But seems like it nails all the other noise down good. Thoughts?